Generally, the microsystems designated MEMS and/or NEMS, for micro and/or nanoelectromechanical systems, are components fabricated by means of microelectronics fabrication processes and certain dimensions of which may range from a few tens of nanometers to a few hundred microns.
A great deal of research has been carried out on these components because they allow functionalities (sensors or actuators) to be obtained that were difficult to obtain with “conventional” microelectronic components, or achieve a comparatively better performance. For example, acceleration or pressure sensors have already been commercialized and used in many applications (cars, video games, mobile phones).
Radio-frequency (RF) components represent another field of application of MEMS. Mention may be made offhand of SAW or BAW resonators for filtering applications in the acquisition or receiver chain of an RF communications module. Such components have already been commercialized, as have high-frequency MEMS resonators implemented in time bases of electronic circuits.
One of the objectives of RF communication is to design communication modules that may have their frequency adjusted. In other words, the operating frequency of the communication module may be adjusted in order to comply with various communication standards.
Electrostatically actuated resonators are one potential solution for producing adjustable filters, which are the basic building blocks of adjustable communication modules.
Examples of filters produced using networks of resonators are already known—see patent application FR 2 929 775. In this patent application the dispersion in resonant frequency due to manufacturing process variability is used to produce a band-pass filter, the pass band of which is thus set by dimensional variations induced by technological dispersion between nominally identical resonators. This type of configuration therefore relies on technological dispersion, which is random and uncontrollable.
Patent application EP 2 197 106 for its part describes a MEMS/NEMS device comprising resonators electrically connected in series, but these resonators are addressed individually at a potential Vi. There are therefore as many actuation voltages as there are resonators. Such an n-resonator device requires n+2 regulating voltages [Ve, Vi (with i ranging from 1 to n), Vdc], which may be particularly disadvantageous in the case of a network comprising many resonators.